In electronic systems, it is often desirable to be able to replace a printed circuit board or other subsystem without disabling power to the system. This process is typically referred to as “hot swapping.” Hot swap systems can be implemented to allow addition or replacement of components in a variety of applications. For example, in computer systems, hot swapping will allow the replacement of a board or the addition of a new board in the system without loss of information in volatile memory in the system, without requiring rebooting the system, etc. In systems such as communication systems and the like, where a plurality of boards of similar function are plugged into a motherboard, boards may be hot swapped or additional boards added without shutting down the system. This allows maintenance and upgrading without interfering with communications or other functions in channels serviced by the remaining boards in the system.
A hot swap controller is a circuit that enables an electronic device to be safely inserted into (and removed from) a connector of a host system (e.g. a computer, a server, a communication device, a storage unit, etc.) while the host system is operational. Hot swap controllers are generally designed to limit inrush current to the electronic device that could damage or cause a malfunction in the electronic device or the host system, thereby enabling safe insertion of the electronic device into the host system or removal of the electronic device from the host system, without interrupting operations of the host system.